Airborne Pheromone Quantification in Treated Vineyards with Different Mating Disruption Dispensers against Lobesia botrana

Abstract

Mating disruption (MD) is widely used against the European grapevine moth (EGVM), Lobesia botrana (Denis and Schiffermüller; Lepidoptera: Tortricidae), by installing passive dispensers or aerosol devices. The present work reports a new sampling and quantification methodology to obtain absolute data about field airborne pheromone concentration based on air samplings and sensitive chromatographic-spectroscopic methods. Samplings were performed in fields treated with passive dispensers or aerosol devices at different moments throughout the crop cycle to study how they act and how the disruption is triggered. Moreover, pheromone adsorption and releasing capacity of vine leaves were studied to elucidate their role in the disruption. Although both types of dispensers were effective in limiting the damage inflicted by EGVM, they performed differently and provided different airborne pheromone concentration profiles. Results also proved that leaves were able to adsorb and release part of the airborne pheromone acting as subsequent and additional pheromone sources. This fact could explain the different concentration profiles. Moreover, our results suggest that lower pheromone emission than that of the current passive dispensers still could provide an adequate performance in the field. Competitive mechanisms involved in MD using both dispensers, the dynamics of the airborne pheromone throughout the time and the importance of the canopy are discussed.

Production of Volatile Moth Sex Pheromones in TransgenicNicotiana benthamianaPlants

“…However, only a small portion of the plant pheromone content can be detected in the environment after a 48h incubation. Typically, mating disruption strategies require daily release rates between 20 and 500 mg Ha -1 day -1 (Alfaro et al, 2009;Gavara et al, 2020). Our data indicates that the maximum release rates per biomass unit are around 20 µg Kg plant -1 day -1 , therefore it would require between 1,000 Kg and 25,000 Kg of pheromone-producing intercropping biomass per Ha for effective mate disruption.…”

“…Due to the abundance of compounds structurally related to the pheromone in the samples, a straight chain fluorinated hydrocarbon ester (heptyl 4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluorononanoate; TFN) was selected as the internal standard to improve both sensitivity and selectivity for MS/MS method optimization. TFN was synthesized as described in Gavara et al (2020).…”

Pheromone Deployment Strategies for Mating Disruption of a Vineyard Mealybug

“…ficus densities or in the first years of MD program establishment. There is also a need to better understand the field longevity on grape leaves of pheromone delivered via flowable applications or aerosol devices (e.g., Knight and Larsen 2008 , Gavara et al 2020 ), the adult male mealybug flight patterns in relation to emitted plumes (e.g., Huang et al 2013 , McGhee et al 2014 , Baker et al 2016 ) and the combined impact of MD and selected insecticides, especially delivered in a tank mix with a flowable pheromone suspension (e.g., Knight 2010 , Suckling et al 2016 ). A common goal of these research directions is to reduce overall costs of Pl.…”

Laboratory investigation of pheromone pre‐exposure in Lobesia botrana males indicates minor role of desensitization in the field

“…For each target compound—TFN (the internal standard) and EGVM pheromone, ( E , Z )‐7,9‐dodecadien‐1‐yl acetate—the MS/MS method was optimized in tests carried out previously (Gavara et al, 2020) by selecting the precursor ion and the product ions that provided the highest selective and sensitive determinations: 393‐373 and 164‐79, precursor–product ions (m/z) employed to obtain the chromatographic areas for TFN and ( E , Z )‐7,9‐dodecadien‐1‐yl acetate, respectively.…”

“…(Carlet, Valencia, Spain). A straight chain fluorinated hydrocarbon ester-heptyl 4,4,5,5,6,6,7,7,8, 8,9,9,9-tridecafluorononanoate (TFN)-was selected as an internal standard for airborne pheromone quantification to improve both sensitivity and selectivity for the spectrometric method optimization (Gavara et al, 2020).…”